Pathophys Test 2

  1. Compare characteristics of benign and malignant neoplasms. (p.26)
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  2. Describe 3 phases of chemical carcinogenesis. What takes place and/or influences each stage? (p.27)
    • Initiation – alteration of genetic material of the cell
    • o Usually result of covalent reaction between carcinogen, or some unknown factor, and DNA
    • o Occurs quickly in dose-related fashion after single exposure
    • o Usually affects only small number of cells
    • o Occurs more frequently in rapidly proliferating tissue
    • o Considered an irreversible event
    • o Susceptible to promotion
    • o Cancer = result of multiple mutations, NOT just one
    • Promotion – initiated cells begin to express genetic changes
    • o Cells begin to proliferate but growth is not yet autonomous
    • o Growth seems to depend on presence of promoting stimulus
    • Progression – development of tumor’s metastatic potential
    • o Autonomous cell growth – independent of the promoter
  3. What are 3 classes of genes associated with pathogenesis of cancer? (p.25)
    • Oncogenes
    • Tumor suppressor genes
    • DNA damage repair genes (mutator genes)
  4. Oncogenes
    • Altered protooncogenes
    • Genes that have potential to accelerate cell division
    • “Gain of function” not dependent on body’s need for more cells
  5. Tumor suppressant genes
    • Genes that slow or inhibit cell growth
    • For example, if one has enough brain cells or liver cells, these cells stop cell proliferation
    • Should mutations occur in these genes, cells can start to grow uncontrolled
  6. DNA damage repair genes
    (mutator genes)
    • Function to maintain integrity of normal genome
    • Array of genes that function in combination to locate and repair DNA damage that may occur during replication, during normal cellular metabolism, or damage due to chemicals, viruses, radiation, etc.
    • Big trouble when mutations occur in these genes – now mutations will accumulate
    • If occur in tumor suppressor genes --> uncontrolled cell growth --> genomic instability = NOT good
  7. What are protooncogenes? (p.25)
    • Genes that regulate normal cell growth and differentiation
    • In most of our cells, these genes are NOT working; when we have enough cells, they turn off
  8. What factors have potential of transforming protooncogenes to oncogenes – genes linked to cancer?
    • Mutations can activate protooncogenes to oncogenes – genes that now have potential to accelerate cell division and that “gain function”
    • Not dependent on body’s need for more cells
    • Mutations caused by: chemicals, viruses, free radicals, irradiation, diet-related, genetics
  9. What genes are associated with risk of breast cancer and ovarian cancer?
    • BRCA 1
    • BRCA 2
  10. RNA Viruses linked with development of cancer
    • Human T Cell Leukemia Virus 1 (HTLV1)
    • - Similar to AIDS– infects CD4 cells (helper T cells)
    • - Ultimately become neoplastic transformations --> T-cell leukemia /lymphoma
    • Hepatitis C – carries high risk for cirrhosis of the liver, hepatocellular carcinoma, liver failure
  11. DNA Viruses linked with development cancer
    • Human Papillomavirus (HPV)
    • - In U.S., most common STD
    • - About 100 different types of papillomaviruses
    • - Some associated with benign papillomas like warts on skin
    • - Others associated with cervical cancer and cancer of anogenital regions
    • - Also oral and layrngeal cancers
    • Epstein-Barr Virus (EBV)
    • - Cancers associated with this virus:
    • Burkitt lymphoma (African), B-cell lymphoma (immunosuppressed individuals), Nasopharyngeal carcinoma
    • Hepatitis B Virus (HBV)
    • - Associated with hepatocellular carcinoma
Card Set
Pathophys Test 2